This topic covers acute, usually community-acquired respiratory infections that spread from person to person: influenza, COVID-19, respiratory syncytial virus (RSV), pertussis, acute bronchitis and bronchiolitis, and acute pharyngitis/tonsillitis. Pneumonia itself is covered in its own topic, but any of these infections can progress to pneumonia, sepsis, or respiratory failure, and the nursing priorities overlap.

Common mechanism: the organism invades respiratory epithelium, causing inflammation, mucus production, loss of ciliary clearance, and airway edema. Fever, cough, and sore throat reflect the inflammatory response. In older adults and people with chronic heart or lung disease, a "mild" viral infection can tip an already limited respiratory reserve into hypoxemia and decompensation.

Pertussis stages

1. Catarrhal (1–2 weeks): runny nose, mild cough — most contagious, rarely recognized
2. Paroxysmal (1–6 weeks or longer): bursts of rapid coughing, inspiratory "whoop," post-tussive vomiting, exhaustion; adults often have no whoop
3. Convalescent (weeks to months): gradual recovery

High-risk groups for complications: adults ≥ 65 years, pregnancy, infants, chronic lung disease (COPD, asthma), heart disease, diabetes, immunosuppression, residents of long-term care facilities, and obesity.

Subjective

• Sudden fever, chills, myalgia, headache, fatigue (influenza)
• Sore throat, painful swallowing, hoarseness
• Cough — dry or productive; coughing spells with vomiting (pertussis)
• Loss of taste or smell (COVID-19)
• Exposure history: sick contacts, travel, animal/poultry contact, vaccination status

Objective

• Temperature, respiratory rate, heart rate, blood pressure, SpO₂
• Work of breathing: accessory muscle use, nasal flaring, inability to speak in full sentences
• Breath sounds: wheezes (bronchitis, bronchiolitis), crackles (suggest pneumonia)
• Pharynx: redness, tonsillar exudate, enlarged tender neck nodes
• Mental status — new confusion in an older adult may be the first sign of hypoxemia or sepsis
• Hydration: dry mucosa, low urine output

Sepsis warning signs: fever or hypothermia, tachycardia, tachypnea, hypotension, altered mental status, cold clammy or mottled skin, decreased urine output. This picture is an emergency.

Treatment of high-risk or hospitalized clients with suspected influenza should not wait for test results.

Antiviral therapy for influenza

• Recommended for all hospitalized clients, clients with severe or progressive illness, and outpatients at high risk
• Best started within 48 hours of symptom onset; still beneficial later in hospitalized or severely ill clients
• Oseltamivir (oral) — adult dose 75 mg twice daily for 5 days; reduce dose when creatinine clearance is low. Adverse effects: nausea, vomiting (take with food); rare neuropsychiatric events (confusion, abnormal behavior), especially in young people. Preferred drug in pregnancy and in hospitalized clients
• Zanamivir (inhaled) — not for clients with asthma or COPD (risk of bronchospasm)
• Peramivir (single IV dose) and baloxavir (single oral dose; not recommended in pregnancy; do not take with dairy, calcium, iron, or magnesium products)
• Antivirals also used for post-exposure chemoprophylaxis in selected contacts

COVID-19

• Outpatients at high risk: nirmatrelvir with ritonavir within 5 days of symptoms. Ritonavir causes many serious drug interactions (e.g., some statins, anticoagulants, antiarrhythmics, certain seizure drugs) — a full medication review is required; dose is reduced in kidney impairment; common effect is altered taste. Remdesivir (IV) is an alternative — monitor liver enzymes, kidney function, and heart rate (bradycardia). Molnupiravir is a last-line option and is not used in pregnancy
• Hospitalized clients needing oxygen: dexamethasone — monitor blood glucose, watch for infection and GI bleeding; plus remdesivir or immunomodulators per protocol
• Prone positioning while awake may improve oxygenation in selected non-intubated clients

RSV: supportive care (oxygen, fluids, bronchodilators only if they help). Prevention by vaccination in older and high-risk adults.

Pertussis: macrolide antibiotic — azithromycin preferred (alternatives clarithromycin, erythromycin, or trimethoprim-sulfamethoxazole). Most effective early; after about 3 weeks of cough antibiotics no longer change the course or transmission. Macrolides: GI upset, QT prolongation (check ECG and interacting drugs), liver effects. Close contacts at high risk receive post-exposure antibiotics.

Acute bronchitis: antibiotics are not recommended — it is almost always viral. Symptom relief only.

Streptococcal pharyngitis: penicillin or amoxicillin for 10 days (alternatives for penicillin allergy) to prevent rheumatic fever and abscess.

Sepsis from respiratory infection: oxygen, IV access, cultures and lactate, broad-spectrum antibiotics within 1 hour when septic shock is likely, 30 mL/kg IV crystalloid for hypotension or lactate ≥ 4 mmol/L, vasopressors (norepinephrine first) to keep mean arterial pressure ≥ 65 mmHg.

Listed in priority order.

1. Airway and breathing first
   • Check SpO₂ and give oxygen as needed before other tasks such as cultures, antipyretics, or teaching
   • Raise the head of the bed (semi- to high-Fowler's) to ease breathing unless hypotension requires another position
   • Target SpO₂ generally 92–96%; 88–92% if the client is at risk of CO₂ retention (e.g., COPD) — but never withhold oxygen from a hypoxemic client
   • In clients with COPD or asthma, monitor respiratory pattern, work of breathing, and SpO₂ closely — acute infection is the most common trigger of decompensation
2. Circulation and sepsis response
   • Recognize hypotension, tachycardia, confusion, cold clammy skin → notify rapid response/provider, establish IV access, prepare fluids and cultures
3. Infection control — start transmission-based precautions on suspicion, not only after confirmation (see table below)
   • Mask the client during transport; teach cough etiquette and hand hygiene

1. Medication safety
   • Before the first antibiotic dose, ask about drug allergies (especially penicillins and cephalosporins) and the type of reaction. Observe for anaphylaxis — hives, wheeze, throat tightness, hypotension — and keep epinephrine available
   • Check antiviral timing, kidney function for dose adjustment, and drug interactions
2. Secretion clearance
   • Fluids 2–3 L/day unless restricted (heart failure, kidney disease) to thin secretions
   • Deep breathing, huff coughing, incentive spirometry, early mobility
   • Postural drainage (when ordered): position so the affected lung segment is uppermost so gravity drains it toward the central airways; perform before meals or at least 1–2 hours after eating; have the client deep breathe and cough during and after each position; stop for dyspnea, chest pain, hemoptysis, or falling SpO₂. Avoid head-down positions with increased intracranial pressure, recent eye or brain surgery, or uncontrolled hypertension
3. Comfort and fever
   • Antipyretics for comfort; tepid fluids; rest
   • Sore throat: cold fluids, ice chips, soft cool foods, lozenges, lukewarm salt-water gargles; avoid alcohol-based mouthwash, hot, spicy, or rough foods
4. Hydration and nutrition — monitor intake, output, and daily weight in dehydrated or frail clients

• Annual influenza vaccination for everyone 6 months and older; ideally by the end of October in the Northern Hemisphere. Egg allergy — even severe — is no longer a reason to avoid or delay influenza vaccination; no extra precautions are needed beyond those for any vaccine
• Mild soreness, low-grade fever, or muscle aches after vaccination are expected and short-lived; they are not treated with antibiotics
• RSV vaccine: single dose for adults 75 and older and for adults 50–74 at increased risk (per the 2025 US schedule, which has changed repeatedly — check the current version; other countries follow their own programs)
• Tdap: adults who never received it get one dose, then Td or Tdap every 10 years; every pregnancy, ideally at 27–36 weeks, to protect the newborn
• COVID-19 and pneumococcal vaccines per current national schedule
• Children and teenagers with influenza should not take aspirin (risk of Reye syndrome)
• Cough relief for bronchitis: warm fluids, honey (not for infants under 12 months — botulism risk), humidified air (about 40–60% humidity), avoid smoke. Caffeine and alcohol can worsen dehydration
• Take antibiotics exactly as prescribed for the full prescribed duration; do not share or save them. Report severe or bloody diarrhea (possible C. difficile) rather than self-treating with antidiarrheals
• Rest, fluids, and stay home until fever-free for 24 hours without antipyretics and symptoms are improving; wear a mask around others for several days after returning
• Seek care immediately for difficulty breathing, chest pain, confusion, bluish lips, persistent high fever, or symptoms that improve then worsen (possible secondary bacterial pneumonia)

Escalate immediately for SpO₂ below target despite oxygen, respiratory rate > 30/min, systolic BP < 90 mmHg, or new confusion.

• First action for a client with a respiratory infection: assess breathing and SpO₂, give oxygen as needed
• Influenza and pertussis = droplet precautions; RSV = contact; COVID-19 = N95 plus eye protection, gown, gloves; novel/avian viruses = airborne + contact
• Influenza antivirals work best within 48 hours, but hospitalized and high-risk clients are treated regardless of timing
• Zanamivir is avoided in asthma/COPD; baloxavir is avoided in pregnancy
• Nirmatrelvir with ritonavir: major drug interactions — review every medication
• Yearly flu vaccine, ideally by end of October; egg allergy is not a contraindication
• No aspirin for children or teens with influenza (Reye syndrome)
• Acute bronchitis is viral: no antibiotics; warm fluids and honey help cough
• Check allergy history before the first antibiotic dose
• Postural drainage: affected area uppermost, before meals, deep breathing and coughing with each position
• Sore throat: cold fluids and soft cool foods; avoid alcohol mouthwash and hot foods
• Tdap in every pregnancy protects newborns from pertussis